gl-mirror-push: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/gl-mirror-push - from package: gitolite

You may install the required package with command yum install {package}

Error in other languages:
gl-mirror-push: bevel nie gevind nie
gl-mirror-push: comandă negăsită
gl-mirror-push: comando não encontrado
gl-mirror-push: commande introuvable
gl-mirror-push: command not found
gl-mirror-push: käsku ei ole
gl-mirror-push: không tìm thấy lệnh
gl-mirror-push: komanda nerasta
gl-mirror-push: Kommando nicht gefunden.
gl-mirror-push: kommandot finns inte
gl-mirror-push: komut yok
gl-mirror-push: nie znaleziono polecenia
gl-mirror-push: níor aimsíodh an t-ordú
gl-mirror-push: no se encontró la orden
gl-mirror-push: no s'ha trobat l'ordre
gl-mirror-push: opdracht niet gevonden
gl-mirror-push: parancs nem található
gl-mirror-push: perintah tidak ditemukan
gl-mirror-push: príkaz nenájdený
gl-mirror-push: příkaz nenalezen
gl-mirror-push: команда не найдена
gl-mirror-push: командата не е открита
gl-mirror-push: 命令找不到
gl-mirror-push: コマンドが見つかりません